Track link



July 19, 1932.

w K. MCMILLA-N ET AL TRACK LINK Filed June 9, 1930 3 Sheets-Sheet 1 A TTORNEYS July 19, 1932. vy. K. MCMILLAN ET AL 1,863,148

TRACK LINK Filed June 9, 1930 3 Sheets-Sheet 2 INVENTOR.

8 w WMCAJ.

A TTO RNEYS.

July 19, 1932. w. -'K.'. MCMILLAN ET Al.

TRACK LINK 5 Sheets-Sheet 3 Filed June 9, 1950 INVENTORQ 2%. W Man/w,

4 I 4 I I I 9 B w- J ATTORNEYS.

Patented July 19,1932

uNirEn sT 'rEs wEsLEY K. MCMILLAN AND JACOB s. 'wALcm E SAN EEAncIsco, CALIFORNIA; As-

SIGNORS, BY DIRECT .AND MEsnE ASSIGNMENTS; TO MoMILLAN-MILLER ROAD MA- CHINERY-INC., CORPORATION OF CALIFORNIA TRACK LINK Application filed June 9,

This invention relates to atrack link such as used in self laying track trailers, tractors, and like vehicles. 7 i l The object of the present invention is to generally improve and simplify the construction and operation of tracklinks of the character described;- to provide a track in which all links are identical in construction; to provide a track consisting of .a plurality of pivotally connected links in which the links are free to swing abouttheir pivots in one direction but limited in their pivotal movement in the opposite direction; to provide a track in which the assembled links present a curved orarcuate surface with relation to the ground to provide atrack-link in which pin wear is reduced to a minimum; to provide a track link having a. shoe. or

grouserwhich functionsas a traction mem- 20, ber and as a housing and enclosure for the linkpins; to provide a double, interlock be tween each pair of links which extends across the entire width of the links and which function to support the links so as to presentan arcuate traction surface; and further, to provide interlock between the links whereby the link pins are relieved of shear action when the links are in engagement with the ground surface. V 3Q The invention is shown by way of illustration in the accompanying drawings, in which Fig. 1 is a side elevation showing the links assembled to present a track surface. said elevation also showing the idler wheelsand the frame in which they are journaled.

Fig. 2 is a perspective view of one of the links showing the type of link employed on trailers,

Fig- 3 is a perspective view of the type of link employed on tractors,

Fig. 4 is a longitudinal. vertical section of a plurality of connected links showing the position they assume when in engagement .with a traction surface,

Fig. 5 is a similar section showing the position assumed bv the links when passing around the idler wheels, and

Fig. 6 is a cross section of the track struc- Lture shown in Fig. 1. r

as indicated at 4 which 1930. Serial No. 459,897. f

Referring to the drawings in detail and particularly Figs. 2 and 3, :A' and 13 indicate. a pair of interspaced link bars,'which terminate at one end in bearing lugs 2 and at their opposite ends ina bearing sleeve 3. A shoe or grouser C is cast link bars A and B and the. lugs 2. Bearing PATENT "OFFICE j as integral with the sleeve 3 is also cast integral with the link bars and a rigidfconnection is accordingly formed between the link bars. The upper edges of the respective links present flat surfaces such are engaged by the flanges 5 of the driving sprockets oridler wheels'as the case may be but as two inter spaced idler wheels are shown at each bight end of the track, see Fig. '6, guide flanges 6 are provided to maintain the track in alignment between the wheels. 9

The links are identical in'construction and the only machining required is that of drilling the bearing lugs 2 as indicated at? and boring the bearingsleeve 3 to permit insertion of a bushing 8.. The links are assembled by inthe bearinglugs 2 of an adjacent link and then connecting them by inserting a link pin 9, the pin being secured by being driven through the lugs 2. The bearing sleeve-3 is free on the pin and pivotal movement between the links is accordingly permitted.v T

One of the important features of the presentinvention is-that of providing a plurality of-Jidentical links which when assembled as. shownin Fig. 1 willpresent an arcuate traction. surface such as indicated by the. dotted line 10 -10. This is accomplished by forming interlocks between the links. This interlock is accomplished as follows: Formed on each bearingsleeve 3 is a lug 11 which extends from .end to end thereof. This lug when the links are assembled projects in under shoul-f bythe-rearfedge' li of .the traction shoedis posed in frontthereof; hence when the links are assembled and are in engagement with the ground surfaceas shown in Fig. 1 aninterlocking connection is formed bythe lug 11, and shoulderlla, and an interlock isalso formed between the rear edge of shoe 12 and shoulder 12a thus preventing thelinks from swinging about their pivots to assume a horizontal position. movement between the links being such that an arcuate surface is presented to the ground as indicated by the dotted line 1010. The

load of the tractor or the trailer is. of course carried by the flanges 5 of the idler wheels." This load is in turn transmitted to thetrack surfaces 4' of the links; This load due to the arcuate, surface presented would tend to transmit a shearing action to the link pins but such shearing action is avoided by pro viding interlocks between the links at the ends thereof.

position shown in Fig. l, or in other words,

when the members llaand 12a are engaged with the memhers'll and 12 respectively, and

' endwisemovement between the links is accordingly taken up by the shoulders2a and 2b, hence relieving the link pins of any shearing action and in factof anyload action.

The: only time the link pins can be subjected to load willbe when the track is used on the tractor. 1 In that case'the links and B will be provided with rounded exterior lugs such as shown at '15 and 16. These lugs Will be engaged by the teeth'ofthe driving sprockets and when so engaged a pull will naturally be exerted between the links tending to separate them. Such separating movement is of course transmitted as a load to the pinsand with theholes 7 in the bearing lugs 2 and 2a,

itis the only load to which they will be subjected. The lugs 15 and 16 are shown as havinghollow centers which are in alignment 'ermittin insertion and removal of link b I pins 9. v j

If reference is made to Figs. 2,3 a-nd i it will be noted that pin wear is'reduced to a minimum not only because of the endwise interlock formed between the links which eliminates any shearing action of the pins but it is also dueto the fact that the grousers or: shoesC form an enclosing housing which The amount. of pivotal These interlocks are; formed by the rounded ends-2a of the bearing-lug ends of the links 2 and by similarly rounding the'opposite ends of the links as indicated at 222. The two rounded shoulders thus formed engage each other when the links assume the may be resorted to within the scope of the appended claim. Similarly, that the ma terials and finishes of the several parts employed maybe such as the manufacturer may decide,- orvarying conditions or uses may demand. V I v Having thus described ent is. i p v i i In a structure of the character described,

a track consisting of a plurality of connected our invention, what .we claim and desire to secure by "Letters Pat:

links, each of which comprises a pair of inter spaced link bars, said bars terminatingin bearingjjlugs atone vfend, a bearing sleeve formed integrally, with and connecting the opposite ends of the link bars, a shoe extending crosswiseof the, link barsand extending outwardly beyond them, said shoe being fornied integrally with the bars and themaj or portion of said shoe being curved, the common axisof saidbearing lugs being the center of curvature, said shoes also being semicylindrical in contour between the said'lugs to form a pocket for the reception of the bearing sleeve of an adj'acent linkpositioned be-'' tween the bearing-lugs, allink pin pivotally connecting the' 'bearing lugs of the link with the bearing sleeve of an" adjacent link, stop substantially excludes dirt and grit. The in-; V

terlocking connection formed between the links by' means of the shoulders 11a, 12a and I traction surface.

(iii,

""the lugs 11 and 12 is animportantffeature I V ash; causes the links-to present an arcuate I Such a surface eliminates; 1

the, use of intermediate trucks between the idler wheels'thereby re'ducing'weight and costoflconstructionw and it furthermore permits ready-turning or steering 'of vehicles ofthis character. I

While certain features of the presentinvention are more or less specifically described, we wish it understood that various changes ciao 

